When my wife had our first baby, I, like many new dads, discovered that infants now come with carrying cases. There's the Baby Bjorn, for strapping Junior to your chest; the cloth sling, for the hunter-gatherer look; and the backpack, for the man who prefers to pretend that his child is camping gear.

The baby carrier is a symbol of a generation of dads--the Baby Bjorners--who, because of spouses' careers, the desire to be involved in their kids' lives, divorce or simple fairness, are doing more of the physical work of parenting. But it's also become a ubiquitous TV and movie sight gag. Comical dudes wearing babies have been on posters for the movies The Hangover and What to Expect When You're Expecting; they're on NBC's fall pilot Guys with Kids, whose three dads hang at a bar with baby luggage around their midsections; and they're on ABC Family's new sitcom Baby Daddy, about a 20-something bachelor struggling to raise a baby left on his doorstep by his ex-girlfriend. Happy Father's Day, dads of America! Pop culture thinks you look really stupid trying to care for the babies you made!

In real life, the hands-on dad is no longer an oddity: 32% of fathers with wives in the workforce were regular caregivers for kids in 2010, up from 26% in 2002; 20% of dads with kids under 5 are the primary caregiver. Society is getting used to the stroller-wrangling, sippy-cup-juggling dad.

But TV's still working on it. TV dads were present at the birth of the medium--or at least sitting in the waiting room, handing out cigars--but change has come to them slowly. Ward Cleaver and Cliff Huxtable perched on the ends of beds and dispensed advice. Dad was an executive role, the big-picture guy. Later, guys like Homer Simpson and Al Bundy were beer-drinking cautionary tales--postpatriarchs without a role or clue.

Now, with fatherhood more about the in-the-trenches work of lunchmaking and bottom wiping, the baby-wearing sight gag suggests an anxiety that the nurturing role turns men into girls. Having a baby around your waist, the joke goes, makes it hard to hold a beer and high-five your bro while watching the game. You're burdened, ungainly; your profile is a pregnant woman's. That baby you're wearing is human drag.

Much dad humor today is based on the premise that it's unnatural for men to be good at caring for kids. In Baby Daddy, Ben (Jean-Luc Bilodeau) changes his first diaper using goggles, duct tape, rubber gloves and tongs. (His childless female friend, of course, takes to it instantly.) The same attitude pervades commercials. Huggies' recent campaign "The Dad Test" boasted that its diapers and wipes are so good, men can use them without help from their wives. In Guys with Kids, meanwhile, stay-at-home dad Gary (Anthony Anderson) commiserates with a female friend about being unappreciated by their working spouses: "And then they have to take an emergency call from work. Just when it's bath time!" The only thing that makes that a joke is that a dad--a man! with a penis!--is saying it.